Question

3 identical rectangular prisms are stacked on the top of each other as shown in the given diagram. What will the combined surface area of the structure formed be?

• A. 332 sq units
• B. 364 sq units
• C. 264 sq units
• D. 324 sq units

Answer 1

The correct option is A 332 sq units


Let $l$, $w$, and $h$ be the corresponding length, width, and height of one rectangular prism as shown above.
To find the total surface area of the structure, let's combine all three rectangular prisms into a single structure with dimensions shown below.

Here, length ($l$) = 10 units, width ($w$) = 4 units, and height ($h$) = 9 units.
Therefore, the total surface area $=2\times (lw+wh+hl)$
$=2\times (10\times 4+4\times 9+9\times 10)$
$=2\times (40+36+90)$
$=2\times 166$
$=332\text{sq units}$